Latch assembly for a double door

Abstract

A latch assembly ( 10 ) is mounted to a follower door ( 275 ) of a double door ( 257 ) and includes a latch ( 231 ) and a pressing board ( 453 ) pivotably received in a cutout ( 411 ) of the latch ( 231 ). When the follower door ( 275 ) moves from an open position to a closed position, a pressing side ( 457 ) of the pressing board ( 453 ) is pressed by a top beam ( 35 ) of a door frame ( 31 ). The pressing board ( 453 ) pivots and presses against a bottom face ( 413 ) of the cutout ( 411 ) of the latch ( 231 ), moving the latch ( 231 ) from an unlatching position to the latching position until the pressing side ( 457 ) of the pressing board ( 453 ) completely enters the cutout ( 411 ), and then a slant face ( 236 ) of the latch ( 231 ) presses against the door frame ( 31 ), causing movement of the latch ( 231 ) from the latching position to the unlatching position.

The invention claimed is: 
     
       1. A latch assembly comprising: a base including two sidewalls and an intermediate wall extending between the two sidewalls, with a slot defined in the intermediate wall, with the intermediate wall of the base adapted to be mounted to an end face of a follower door of a double door further including a primary door, with the follower door including an interior space, with the two sidewalls adapted to be received in the interior space of the follower door, with the follower door pivotable between a closed position and an open position; a movable member received between the two sidewalls of the base and movable along a first axis between an engagement position and a disengagement position, with the movable member including two lateral walls spaced from each other along a second axis perpendicular to the first axis, with the movable member further including a connecting portion extending between the two lateral walls, with the movable member further including an actuating groove defined in the connecting portion, with the actuating groove aligned with the slot of the base; a latch including an engagement end fixedly coupled to the movable member, with the latch further including a locking end having a slant face, with the latch further including a first surface and a second surface spaced from the first surface along the second axis, with the latch further including a cutout extending from an end face of the locking end toward the engagement end along the first axis and terminating in a bottom face spaced from the engagement end, with the bottom face located between the locking end and the engagement end, with the cutout extending to the first and second surfaces and the slant face of the latch, with the latch and the movable member jointly movable, with the latch movable along the first axis between a latching position corresponding to the engagement position of the movable member and an unlatching position corresponding to the disengagement position of the movable member, with the locking end of the latch in the unlatching position being adapted to be received in the follower door, with the locking end of the latch in the latching position adapted to extend out of the follower door into a groove in a top beam of a door frame to which the follower and primary doors are pivotably mounted; a pressing board received in the cutout of the latch, with the pressing board including two lateral sides spaced from each other along a third axis perpendicular to the first and second axes, with the pressing board further including a pressing side extending between the two lateral sides, with the pressing side having first and second ends, with the pressing board further including an abutment side extending between the two lateral sides, with the abutment side including a first end connected to the second end of the pressing side and a second end, with the pressing board further including an arcuate side extending between the two lateral sides, with the arcuate side including a first end connected to the second end of abutment side and a second end connected to the first end of pressing side, with a pivotal portion formed between the second end of the pressing side and the first end of the abutment side, with an actuating portion formed between the second end of the abutment side and the first end of the arcuate side, with the pressing side facing the first surface of the latch in the latching position, with a portion of the pressing side adjacent to the first end of the pressing side located outside of the slant face of the latch, with the abutment side facing the bottom face of the cutout of the latch in the latching position; and a coupling member including a top face and a bottom face spaced from the top face along the first axis, with the coupling member further including a coupling hole extending from the top face through the bottom face of the coupling member, with the pivotal portion of the pressing board pivotably mounted to the coupling member, with the latch and the pressing board extending through the coupling hole, with the coupling member adapted to be fixed to a top face of the follower door, wherein when the follower door is in the open position, the latch is not aligned with the groove of the top beam and is in the latching position, wherein when the follower door is in the closed position, the latch is aligned with the groove of the top beam and is in the latching position, wherein when the follower door moves from the open position to the closed position, the pressing side of the pressing board is pressed by the top beam of the door frame, the pressing board pivots such that the actuating portion presses against the bottom face of the cutout of the latch, moving the latch towards the unlatching position until the pressing side of the pressing board completely enters the cutout of the latch, and then the slant face of the latch presses against the door frame, causing further movement of the latch such that it reaches the unlatching position, wherein the latch is moved from the unlatching position to the latching position when the follower door is moved into the closed position such that the latch extends into the groove of the top beam, wherein when an end face of the primary door is not aligned with the end face of the follower door, the movable member is moved from the engagement position to the disengagement position by the actuating groove to cause movement of the latch from the latching position to the unlatching position. 
     
     
       2. The latch assembly as claimed in  claim 1 , with the pivotal portion of the pressing board including a width along the third axis smaller than a spacing between the two lateral sides of the pressing board along the third axis, with the pressing side, the abutment side, and the pivotal portion defining two stop portions spaced from each other along the third axis, with a pivotal seat formed on the bottom face of the coupling member and located along a periphery of the coupling hole of the coupling member, with the pivotal portion of the pressing board pivotably mounted to the pivotal seat of the coupling member, with the pivotal seat including two outer surfaces, wherein when the latch is in the latching position, the two stops portions abut against the outer surfaces of the pivotal seat of the coupling member, preventing the actuating portion of the pressing board from disengaging from the cutout of the latch.